HOMESTEAD, Fla.—When Brad Keselowski finally walked into his postrace press conference two hours after winning his first Sprint Cup title, he wasn’t lugging the championship trophy.

Instead, he raised an oversized bottle of champagne above his head—one with the Sprint Cup championship logo on the front. “I brought it with me,” he quipped.

About an hour earlier, Keselowski had hoisted a huge, half-empty glass of beer as he was interviewed on live TV, tipping his glass to fans and encouraging them to join the party.

Keselowski’s revelry had to make team owner Roger Penske, one of the most buttoned-up entrepreneurs in sports, if not all of corporate America, a bit nervous.

But after Keselowski had just delivered Penske his first NASCAR championship in 30 years, what could he say?

“When you have won the NASCAR championship, you give him a little wider path,” a grinning Penske said. “And he’s taking it side to side. It’s all good.”

Keselowski had every right to party after reaching the pinnacle of NASCAR, and beating five-time champion Jimmie Johnson to do it.

Keselowski capped a marvelous championship run Sunday night, cruising to a pedestrian 15th-place run in the season finale to finish off Johnson. With his season ended in the garage, Johnson and his Hendrick Motorsports team finally buckled under the pressure of trying to fend off and keep up with Keselowski.

Afterward, Keselowski circled Homestead-Miami Speedway waving an American flag. Then the party began.

At least Keselowski was downing Miller beer, no doubt making his high-profile sponsor happy.

“I saw him as great driver and a great tactician,” Penske said. “I didn’t know that he was commercially viable.”

There’s a lot Penske didn’t know about his 28-year-old star when he hired him four years ago. He found out quickly that either Keselowski had tremendous drive and determination, or a huge ego.

“He came in and said, ‘I want to help you build a championship team,’” said Penske, who has won 12 IndyCar championships and 15 Indy 500s but had never won a NASCAR Cup title.

“That’s how we started and there’s no question that he’s delivered beyond what we expected.”

Penske had come close to winning championships with Hall of Fame driver Rusty Wallace in the 1990s, but his organization had become stagnant over the years, falling behind the elite teams with drivers Ryan Newman and Kurt Busch.

But in late 2009, he hit the jackpot with Keselowski.

“He has galvanized the team in terms of leadership,” Penske said. “You can be a big shot … but he’s a pure team player.”

Penske then paid Keselowski perhaps the greatest compliment he could in the NASCAR world, comparing him to perhaps the greatest champion the sport has ever seen.

Short of Richard Petty, there’s no bigger legend in NASCAR than Dale Earnhardt.

Penske says Keselowski did for his organization what Earnhardt did for Richard Childress Racing.

“Look at what they built,” Penske said of Earnhardt and Childress, who won six Cup titles together.

“I see them a lot alike,” he said of Keselowski and Earnhardt. “They are the glue, they are the builders.”

Many believe it won’t be the only championship Keselowski and Penske will celebrate together. Keselowski is only the third driver in his 20s to win a championship in the past 28 years.

“I think he’s going to be a multi-champion, and I hope we can continue to grow on this and go on and do it again,” Penske said.

Keselowski obviously is on board. He and crew chief Paul Wolfe already are pushing Penske on issues for next season.

“I feel like the best is yet to come. I really do,” he said. “I feel like this team, we can do anything we set our mind to.

“I just feel so fortunate to be where I’m at, in life and in racing. You are a product of who you surround yourself with, and I’m surrounded by the best. That’s as good as life gets.”

Penske sat side-by-side with Keselowski Sunday night, smiling and grinning as his colorful driver regaled the media with story after story from his racing career. (The alcohol had kicked in by that point.)

Keselowski, of course, had his infamous cell phone with him—the one that cost him $25,000 last week for tweeting during the race at Phoenix. When he pulled it out to see how many Twitter followers he had accumulated throughout the night, he was not surprised to find that the number topped 6,000, putting him over 330,000.

All he was missing was the big beer glass he had been chugging from in victory lane.

“I’m going to get it back tonight,” he joked.

That’s NASCAR’s new fun-loving, beer-chugging champion. There is only one thing he likes more than his cell phone and a good time—winning races and championships.

“I want to come back next year and be better than ever and find that next level of success,” he said.

Oh, and there is one more thing he would like.

“I’ve always wanted to date a celebrity,” he said. “I’m just throwing that out there. I think that would be cool. … Not a Kardashian, though.”